Title:
ELECTRICALLY HEATED WEATHERPROOF WIPER BLADE
United States Patent 3619556


Abstract:
A windshield wiper blade and arm assembly in which the blade comprises a pressure-distributing superstructure including a number of pivotally connected levers and a flexible backing strip for retaining a rubber squeegee element. The superstructure and backing strip is enclosed by an envelope of rubber or rubberlike material with a squeegee element extending exteriorly thereof. A heating element is disposed in heat exchange relationship with respect to the envelope and is connected to a source of electrical energy through a detachable connection exteriorly of the rubber element. An electrical conductor extends from the above-mentioned connection along the length of the wiper arm to a connecting terminal on the cowl of a motor vehicle.



Inventors:
Deibel, Raymond A. (West Falls, NY)
Riester, William C. (Williamsville, NY)
Application Number:
04/874266
Publication Date:
11/09/1971
Filing Date:
11/05/1969
Assignee:
TRICO PRODUCTS CORP.
Primary Class:
Other Classes:
15/250.44, 219/202, 219/522, 219/549
International Classes:
B60S1/38; (IPC1-7): B60L1/02
Field of Search:
219/203,522,549 15
View Patent Images:
US Patent References:
3408678Windshield wiper assembly1968-11-05Linker
2746077Electrically-heated windshield wiper1956-05-22Higgins
2727271Snow blade1955-12-20Oishei et al.



Primary Examiner:
Staubly R. F.
Claims:
What is claimed is

1. A windshield wiper assembly comprising a flexible wiping element including an anchoring bead extending longitudinally along its entire length, a flexible-channelled backing strip coextensive with said anchoring bead, said backing strip supporting the anchoring bead within the channel thereof, an articulated pressure distributing superstructure comprising a plurality of pivotally connected levers supporting said backing strip, an impervious collapsible, tubular, elastic envelope enclosing said pressure-distributing superstructure and said backing strip, an elongated heating element disposed within the channel of said backing strip intermediate a wall of said envelope and said anchoring bead within the confines of said envelope in direct heat transfer relationship with a wall of said envelope to thereby transfer heat to the interior of said envelope for heating said levers of said articulated backing strip and the atmosphere within said impervious envelope, said wall of said envelope being thin relative to said anchoring bead to thereby pass the greater portion of the heat generated to the interior of the envelope, said heating element including terminal means extending outwardly of said envelope for detachably connecting said heating element to a mating terminal of an energizing source whereby heat is applied to the joints of the articulated superstructure and to the surrounding atmosphere shielded from the car-created stream of cold air to maintain the superstructure free from ice buildup and to permit free articulation of the levers.

2. A windshield wiper assembly according to claim 1 wherein the pressure-distributing superstructure is electrically conducting and one side of said heating element is electrically connected to one terminal of said energizing source through said superstructure.

Description:
BACKGROUND OF THE INVENTION

The invention relates to improvements in cold weather wiper blades for motor vehicles. An elastomeric envelope is provided for protecting the superstructure from accumulations of snow and ice and a heater element is provided in combination with the envelope for melting of ice which may have formed due to accumulation of moisture from condensation. This invention is an improvement on U.S. Pat. No. 2,727,271 by J. R. Oishei et al., issued Dec. 20, 1955, and U.S. Pat. No.2,728,100 by J. R. Oishei, issued Dec. 27, 1955, both assigned to the assignee of the instant invention. In the above-mentioned prior patents it was proposed to protect the relatively movable parts of the pressure-applying and distributing frame, constituting the superstructure, from the weather to preserve the surface-conforming characteristic of the wiper. The blade disclosed in the prior art patents effectively sealed out snow and ice. However certain climates and under certain weather conditions moisture may condense and freeze within the envelope and may cause some obstruction to free movement of the relatively free movable parts.

The wiper blade of the present invention includes a heating element disposed in a protected position between the squeegee element and the pressure applying and distributing frame in heat exchange relationship with the interior of the elastomeric envelope. The heating element extends longitudinally along the length of the superstructure to effectively melt any ice which may have accumulated from frozen condensation, thus permitting free movement of the relatively movable parts of the superstructure. The envelope and the squeegee element both being of insulating material serve as electrical insulators for the heating element. Because the heating element lies in juxtaposition to the elastomeric envelope heat is transferred to the interior of the envelope by conduction and radiation. The wiper is in a position exposed to a relatively rapid windstream created by the motor vehicle. Therefore exposed metallic elements of the superstructure would lose heat rapidly by convection. The shielding provided by the envelope prevents such rapid heat loss and reduces the amount of energy required to provide sufficient heat for melting iced condensation within the envelope.

The principal object of the present invention is to provide a cold weather blade of simple and practical design by which efficient operation of its supporting superstructure is maintained during inclement weather.

Another object of the invention is to provide a heated windshield wiper assembly for cleaning curved windshields having contoured vision areas, in which a surface-conforming frame that is fully enclosed and protected from the weather to maintain a freely flexible and efficient performance.

Other objects and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the preferred embodiment of the present invention.

FIG. 2 is a transverse sectional view taken on line II--II of FIG. 1.

FIG. 3 is a perspective view of a blade of this invention partly broken away.

FIG. 4 is a partly exploded perspective view of the invention with the superstructure and envelope removed.

FIG. 5 is a partial longitudinal section taken on line V--V of FIG. 3.

DETAILED DESCRIPTION

Referring now to the drawings, the blade 10 comprises a flexible body or squeegee element 12 formed of rubber, either natural or synthetic, having a wiping edge 14 along one margin and an anchoring bead or enlargement 16 along its opposite margin. The bead 16 is joined to the body by a reduced neck portion 18.

The blade 10 is supported by a flexible backing strip 20 in the form of a resilient strip having opposed series of retaining fingers 22 arranged along its opposite side margins forming a longitudinal channel 15 for receiving the anchoring bead 16. The flexible backing strip 20 constitutes the lower side and longitudinal frame member of a flexible pressure applying and distributing frame or superstructure 24. The backing strip 20 serves to distribute the applied pressure along the length of the blade and to restore the frame to a balanced state. The upper side of the superstructure 24 may be composed of s series of rockably connected, longitudinal lever members 26, 28 and 30. The free ends of the levers 28 and 30 may engage the backing strip 20. A connector element 36 is fixed on the primary lever 26 for attaching the wiper to an oscillatory wiper arm 38. The arm 38 is biased to resiliently press the wiper against the windshield.

The operation of the wiper should be apparent from the foregoing description. The flexible superstructure, which consists of the several frame members or levers serves to spread the arm applied pressure lengthwise over the backing strip 20 to cause it to yield in conformance to the surface as it rides over the varying curvatures found in the surface contour of the windshield.

A primary purpose of the invention is to preserve the surface-conforming flexibility of the blade carrier frame or superstructure 24 in a practical manner, it being appreciated that wet snow can pack between the relatively movable parts of the frame, if exposed, to obstruct their freedom of action. Or moisture from condensation or rain may accumulate upon such parts and freeze them immovable and render the wiper rigid and therefore useless on a modern curved windshield.

Accordingly then, an envelope or hood 40 is provided to protect the frame and preserve the surface-conforming action of the frame 24. This weather envelope may be open at one end only, or both ends may be open to enable the endwise introduction of the pressure-distributing frame 24 thereinto. The envelope 40 may be of tubular configuration and may follow generally the external configuration of the superstructure 24. It may be formed of rubber or other suitable elastomeric material and provides a thin-walled envelope for the moving parts of the pressure-distributing superstructure 24. The thin walls are elastic and readily flex and stretch, fold and roll as the frame or superstructure folds and unfolds. This wall section will resist the accumulation of ice and snow by breaking the adhesion of ice and snow. A depression in the top wall of the envelope and a mating depression in the upper level of the superstructure is provided for receiving the arm attaching connector element 36. This connector may be of the type shown in U. S. Pat. No. 3,378,874 by Anthony C. Scinta, issued Apr. 23, 1968, assigned to the assignee of the present invention. The underside of the envelope 40 is shaped to form inverted channel 44 to fit within the longitudinal channel of the backing strip 20 and in turn to receive the anchoring bead 16. This is clearly shown in FIG. 2 where it will be observed that by the placement of the wiping blade in the lower side of the pressure-distributing superstructure 24 the endwise introduction of the anchoring bead into the anchoring channel 44 automatically fastens and secures the underside of the hood to the flexible backing. The flexible enclosure enveloping the superstructure prevents substantially all entry of snow and ice between the levers of the flexible superstructure and resists exterior accumulation of snow and ice as well. Under certain adverse conditions condensation of moisture on the flexible levers and residual moisture on the envelope itself could freeze thereby interfering with the operation of the flexible elements.

To prevent such interference there is disposed intermediate the underside of the envelope and the anchoring bead a longitudinal flat striplike electrical conductor having high electrical resistance constituting a heating element 48. Secured to one end of the heating element 48 is an anchoring and terminal member 52 which may be secured by crimped tabs 50 as shown or in any other suitable or desirable manner. The anchoring member 52 is of an electrically conductive material and includes a second pair of tabs 54 extending laterally in opposite directions which are reversely bent and received in recesses 56 formed in the sidewalls of the anchoring bead 16. At its other end the heating element 48 extends outwardly from the envelope 40 and is reversely bent as at 49 so that a leg 51 thereof engages a surface of the metallic backing strip 20 and forms a ground connection for the heater element 48. The anchoring member 52 includes a pair of connecting tabs 57 which embrace and are crimped to electrical conductor 58.

Each open end of the envelope 40 may be closed by a rubber or plastic end cap 60 which is of sufficient expanse to close the end of the envelope and also to block the removal of the anchoring bead 16. The conductor 58 extends through an access opening 59 in one end cap 60 and has at its free end a terminal connector 62. In the preferred embodiment the conductor 58 extends from the end cap 60 inwardly through the envelope 40 and access openings in the superstructure 24 thence outwardly through an access opening in the arm connector 36. At the reversely bent portion 49 of the heating element 48 the end cap 60 exerts sufficient pressure against the leg 51 of the heating element 48 to provide a good ground connection through the superstructure.

The blade assembly 10 may be secured to arm 38 in any suitable or desirable manner as for example the cantilever pin arm-to-blade connector as shown in U.S. Pat. No. 3,418,678 by R. A. Deibel et al., issued Dec. 31, 1968. The arm 38 includes a cantilever pin 64 receivable in transverse opening in the connector 36. Although for purposes of illustration a cantilever pin type arm-to-blade connector is shown, any suitable or desirable type of connection may be utilized in accordance with the broader aspects of the invention. At its other end the arm 38 includes a mounting head 66 for securement to a pivot shaft (not shown) which is in turn mounted for pivotal movement at the cowl of the motor vehicle. The arm 38 includes an electric conductor 66 which may be clipped thereto and disposed in a concealed position. At each end this conductor includes a detachable terminal connection 61, 61'. Terminal 61 at its outer end is detachably connectable to the connector 62. Terminal 61' of conductor 58 at its inner end is detachably connected to a mating connector 70 mounted adjacent the pivot shaft on the cowl of the vehicle. An electrical conductor 72 extends from a power source within the vehicle as, for example, a battery (not shown) to the connector 70.

It is of course obvious that the conductor 72 may be connected to the electrical power source through any suitable switching mechanism as, for example, the wiper motor switch. Thus it will be apparent that when the wiper motor is energized electrical current will flow from the battery to the conductor 72, conductor 68 and the heating element 48 to ground through superstructure 24, connector 36 and wiper arm 38 thereby providing heat within the hooded element. This will melt any ice or snow that may have accumulated during nonuse and iced condensation within the hooded element. The combination of the melting of the snow due to the heat and the flexing action of the envelope prevents any resistance to flexing of the superstructure and thus permits good surface conformance by means of free flexing of the superstructure under all weather conditions. The envelope provides good heat insulation for the metal levers thereby reducing heat loss due to the car created windstream. Therefore a very small amount of energy is consumed to provide sufficient heat to melt any accumulation of ice and snow within or outside the envelope.

Although a certain specific embodiment of the invention has been shown for the purpose of illustration it will be apparent that various modifications and other embodiments are possible within the scope of the invention. It is to be understood, therefore, that the invention is not limited to the specific arrangement shown but in its broadest aspects it includes all equivalent embodiments and modifications.